Vertical-mount electrical power distribution plugstrip

ABSTRACT

A vertical-mount electrical power distribution plugstrip comprises a long, thin plugstrip body with several power outlet plugs distributed along the length of one face. A power input cord is provided at one end, and this supplies operating power to each of the power outlet plugs through individual relay control.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This Application is a continuation of U.S. patent application Ser. No.14/273,358, filed May 8, 2014, titled VERTICAL-MOUNT ELECTRICAL POWERDISTRIBUTION PLUGSTRIP, which is a continuation of U.S. patentapplication Ser. No. 13/230,719, filed Sep. 12, 2011, titledVERTICAL-MOUNT ELECTRICAL POWER DISTRIBUTION PLUGSTRIP, which is acontinuation of U.S. patent application Ser. No. 11/243,701, filed Oct.4, 2005, titled VERTICAL-MOUNT ELECTRICAL POWER DISTRIBUTION PLUGSTRIP,which is a continuation of U.S. patent application Ser. No. 09/930,780,filed Aug. 15, 2001, now U.S. Pat. No. 7,043,543, titled VERTICAL-MOUNTELECTRICAL POWER DISTRIBUTION PLUGSTRIP. The entire disclosures of eachof these prior applications are incorporated herein by reference.

This application is related to U.S. patent application Ser. No.09/732,557, filed Dec. 8, 2000, now U.S. Pat. No. 7,099,934, titledNETWORK-CONNECTED POWER MANAGER FOR REMOTE APPLIANCES, which is acontinuation-in-part of U.S. patent application Ser. No. 09/375,471,filed Aug. 16, 1999, now U.S. Pat. No. 6,711,613, titled REMOTE POWERCONTROL SYSTEM, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/685,436, filed on Jul. 23, 1996, now U.S. Pat.5,949,974, titled SYSTEM FOR READING THE STATUS AND CONTROLLING THEPOWER SUPPLIES OF APPLIANCES CONNECTED TO COMPUTER NETWORKS. The entiredisclosures of each of these prior applications are incorporated hereinby reference.

TECHNICAL FIELD

The invention relates generally to remote power management systems, andmore particularly to electrical power distribution devices and methodsfor conserving the primary rack-mount spaces in a standard RETMA rack.

BACKGROUND

Network server “farms” and other network router equipment have settledon the use of equipment bays in 19″ standard RETMA racks. Many of theseserver and router farms are located at telephone company (TelCo) centralequipment offices because they need to tie into very high bandwidthtelephone line trunks and backbones. So each TelCo typically rents spaceon their premises to the network providers, and such space is tight andvery expensive.

The typical network router, server, or other appliance comes in arack-mount chassis with a standard width and depth. Such chassis arevertically sized in whole multiples of vertical units (U). Each rentedspace in the TelCo premises has only so much vertical space, and so thebest solution is to make best use of the vertical space by filling itwith the network appliances and other mission-critical equipment.

Two kinds of operating power are supplied to such network appliances,alternating current (AC) from an uninterruptable power supply (UPS) ordirect from a utility, the second kind is direct current (DC) from TelCocentral office battery-sets. Prior art devices have been marketed thatcontrol such AC or DC power to these network appliances. For example,Server Technology, Inc., (Reno, NV) provides operating-power controlequipment that is specialized for use in such TelCo premises RETMAracks. Some of these power-control devices can cycle the operating poweron and off to individual network appliances.

Such cycling of operating power will force a power-on reset of thenetwork appliance, and is sometimes needed when an appliance hangs orbombs. Since the network appliance is usually located remote from thenetwork administration center, Server Technology has been quitesuccessful in marketing power managers that can remotely report andcontrol network-appliance operating power over the Internet and othercomputer data networks.

Conventional power management equipment has either been mounted in thetops or bottoms of the server farm RETMA racks, and thus has consumedvertical mounting space needed by the network appliances themselves. Sowhat is needed now is an alternate way of supplying AC or DC operatingpower to such network appliances without having to consume much or anyRETMA rack space.

SUMMARY

Briefly, a vertical-mount electrical power distribution plugstripembodiment of the present invention comprises a long, thin plugstripbody with several power outlet plugs distributed along the length of oneface. A power input cord is provided at one end, and this suppliesoperating power to each of the power outlet plugs through individualrelay control.

An advantage of the present invention is that an electrical powerdistribution plugstrip is provided that frees up vertical rackmountspace for other equipment.

Another advantage of the present invention is that an electrical powerdistribution plugstrip is provided for controlling the operating powersupplied to network appliances.

A further advantage of the present invention is that an electrical powerdistribution plugstrip is provided that allows a network consoleoperator to control the electrical power status of a router or othernetwork device.

A still further advantage of the present invention is that an electricalpower distribution plugstrip is provided for reducing the need forenterprise network operators to dispatch third party maintenance vendorsto remote equipment rooms and POP locations simply to power-cycle failednetwork appliances.

These and many other objects and advantages of the present inventionwill no doubt become obvious to those of ordinary skill in the art afterhaving read the following detailed description of the preferredembodiments which are illustrated in the various drawing FIGS.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an electrical power distributionplugstrip embodiment of the present invention;

FIG. 2 is a functional block diagram of a power manager systemembodiment of the present invention that incorporates the electricalpower distribution plugstrip of FIG. 1 in a TCP/IP network environment;

FIG. 3 is a functional block diagram of four intelligent power modulesin a serial-communication daisy-chain all in a power manager systemembodiment of the present invention that is one embodiment of theelectrical power distribution plugstrip of FIG. 1;

FIG. 4A is a functional block diagram of an intelligent power moduleembodiment of the present invention that is one embodiment of theelectrical power distribution plugstrip of FIG. 1;

FIG. 4B is a functional block diagram of another intelligent powermodule embodiment of the present invention in which a single powermanager is able to simultaneously control four 4-relay boards;

FIG. 5 is a functional block diagram of a single intelligent powermodule that controls several loads with dry-contact relays and can issuean alarm to alert a user when too much current is being demanded by oneload, or all of the loads together;

FIG. 6 is a schematic diagram of an addition to a four port power modulethat can be used to monitor and report the load current being deliveredthrough each power outlet socket;

FIG. 7 is a functional block diagram of a power distribution unitembodiment of the present invention that allows a variety of personalitymodules to be installed for various kinds of control input/outputcommunication; and

FIG. 8 is a functional block diagram of a 4-port intelligent powermodule embodiment of the present invention like those shown in FIG. 7.

DETAILED DESCRIPTION

FIG. 1 represents an electrical power distribution plugstrip embodimentof the present invention, and is referred to herein by the generalreference numeral 100. The electrical power distribution plugstrip 100includes a long, thin housing 102 with one face having a user display104 and a set of RJ-11 control jacks 106. A power input cord 108 isprovided at one end and has an appropriate power plug 110. For example,the power plug 110 is rated for 125 VAC at 30 A. A plurality of poweroutlet sockets 111-126 are provided along a single face of the housing102. The user display 104 preferably provides a digital readout of thetotal input current flowing in on power input cord 108.

The total input current display 104 can be used to advantage by atechnician when installing or troubleshooting a RETMA equipment rack bywatching how much current change is observed when each network applianceis plugged in and turned on. Unusually high or low currents can indicateparticular kinds of faults to experienced technicians.

In alternative embodiments of the present invention, each power outletsocket 111-126 is provided with a current-sensing device that canmeasure the individual load current. Such measurement can then bereported locally on the user display 104, or serially communicated outto a remote location. Which power outlet socket 111-126 to measure canbe user selected by a simple pushbutton associated with each. Other morecomplex selection mechanisms can also be employed.

A first group of power outlet sockets 111-114 are mounted on a firstintelligent power module (IPM) 128. A second group of power outletsockets 115-118 are mounted on a second IPM 130. A third group of poweroutlet sockets 119-122 are mounted on a third PM 132. And a fourth groupof power outlet sockets 123-126 are mounted on a fourth IPM 134. Theuser display 104 and RJ-11 control jacks 106 are mounted on a powerdistribution and user display printed circuit board (PCB) 144. A powertransformer 146 is used to step-down electrical power to the logic powersupply levels needed by the IPM's 128-134, and PCB 144.

The manufacturing and marketing of IPM's 128-134 can be greatly enhancedby making the hardware and software implementation of each IPM the sameas the others. When a system that includes these IPM's is operating, itpreferably sorts out for itself how many IPM's are connected in a groupand how to organize their mutual handling of control and status data inand out.

FIG. 2 represents a power manager system embodiment of the presentinvention, and is referred to herein by the general reference numeral200. The electrical power distribution plugstrip 100 (FIG. 1) isincorporated here, but is shown controlling only one relay and theoperating power to one network appliance. Preferred embodiments of thepresent invention control many such relays and their correspondingnetwork appliances.

A network management system (NMS) 202 is connected by a network 204 to aremote site 206. A power controller 208 forwards operating power througha sensor 210 and relay-switch 212 to a computer-based appliance 214. Asmany of the functional parts of power controller 208 as possible arepackaged in preferred embodiments of the present invention in a packagelike that of the electrical power distribution plugstrip 100 (FIG. 1).Preliminary implementations have packaged the network interfacecomponents in another chassis, e.g., one that rack-mounts in a 19″ RETMAequipment rack at remote site 206.

The operating power being controlled by relay 212 can be the traditional110 VAC or 220 VAC power familiar to consumers, or direct current (DC)battery power familiar to telephone central-office “plant” employees. Anetwork interface controller (NIC) 216 may be used to connect thecomputer-based appliance 214 to the network 204. Such would beespecially true if the computer-based appliance 214 were a server,router, bridge, etc.

The power controller 208 can be configured to operate in a number ofdifferent modes, and such options are selected and stored in aconfiguration memory. The NMS 202 may download configurations to powercontroller 208, and may upload them for editing, archiving, and/orduplication to other power controllers 208 at other remote sites 206.Embodiments of the present invention are directed towards systems andmethods that do such uploading, downloading, editing, archiving, andduplication of power manager configuration files.

The power manager system 200 maintains the operating health of thecomputer-based appliance 214. Such computer based appliance 214 is proneto freezing or crashing where it is effectively dead and unresponsive.It is also some mission-critical assignment that suffers during suchdown time. It is therefore the role and purpose of the power manager 200to monitor the power and environmental operating conditions in which thecomputer-based appliance 214 operates, and to afford managementpersonnel the ability to tum the computer-based appliance 214 on andoff. Such allows a power-on rebooting of software in the computer-basedappliance 214 to be forced remotely from the NMS 202. The operatingconditions and environment are preferably reported to the NMS 202 onrequest and when alarms occur.

The power controller 208 further includes a network interface controller(NIC) 218, and this may be connected to a security device 220. If thenetwork 204 is the Internet, or otherwise insecure, it is important toprovide protection of a network agent 222 from accidental and/ormalicious attacks that could disrupt the operation or control of thecomputer-based appliance 214. At a minimum, the security device 220 canbe a user password mechanism. Better than that, it could include adiscrete network firewall and data encryption.

The network agent 222 interfaces to a remote power manager 224, and itconverts software commands communicated in the form of TCP/IPdatapackets 226 into signals the remote power manager can use. Forexample, messages can be sent from the NMS 202 that will cause theremote power manager 224 to operate the relay-switch 212. In reverse,voltage, current, and temperature readings collected by the sensor 210are collected by the remote power manager 224 and encoded by the networkagent 222 into appropriate datapackets 226. Locally, a keyboard 228 canbe used to select a variety of readouts on a display 230, and also tocontrol the relay-switch 212.

The display 230 and keyboard 228 can be connected as a terminal througha serial connection to the power manager 224. Such serial connection canhave a set of intervening modems that allow the terminal to be remotelylocated. The display 230 and keyboard 228 can also be virtual, in thesense that they are both emulated by a Telnet connection over thenetwork 204.

The NMS 202 typically comprises a network interface controller (NIC) 232connected to a computer platform and its operating system 234. Suchoperating system can include Microsoft WINDOWS-NT, or any other similarcommercial product. Such preferably supports or includes a Telnetapplication 236, a network browser 238, and/or an SNMP application 240with an appropriate NIB 242. A terminal emulation program or userterminal 244 is provided so a user can manage the system 200 from asingle console.

If the computer-based appliance 214 is a conventional piece of networkequipment, e.g., as supplied by Cisco Systems (San Jose, Calif.), therewill usually be a great deal of preexisting SNMP management softwarealready installed, e.g., in NMS 202 and especially in the form of SNMP240. In such case it is usually preferable to communicate with thenetwork agent 222 using SNMP protocols and procedures. Alternatively,the Telnet application 236 can be used to control the remote site 206.

An ordinary browser application 238 can be implemented with MSNExplorer, Microsoft Internet Explorer, or Netscape NAVIGATOR orCOMMUNICATOR. The network agent 222 preferably includes the ability tosend http-messages to the NMS 202 in datapackets 226. In essence, thenetwork agent 222 would include an embedded website that exists at theIP-address of the remote site 206. An exemplary embodiment of a similartechnology is represented by the MASTERSWITCH-PLUS marketed by AmericanPower Conversion (West Kingston, R.I.).

Many commercial network devices provide a contact or logic-level inputport that can be usurped for the “tickle” signal. Cisco Systems routers,for example, provide an input that can be supported in software to issuethe necessary message and identifier to the system administrator. Adevice interrupt has been described here because it demands immediatesystem attention, but a polled input port could also be used.

Network information is generally exchanged with protocol data unit (PDU)messages, which are objects that contain variables and have both titlesand values. SNMP uses five types of PDUs to monitor a network. Two dealwith reading terminal data, two deal with setting terminal data, andone, the trap, is used for monitoring network events such as terminalstart-ups or shut-downs. When a user wants to see if a terminal isattached to the network, for example, SNMP is used to send out a readPIXY to that terminal. If the terminal is attached, a user receives backa PDU with a value “yes, the terminal is attached”. If the terminal wasshut off, a user would receive a packet informing them of the shutdownwith a trap PDU.

In alternative embodiments of the present invention, it may beadvantageous to include the power manager and intelligent power modulefunctions internally as intrinsic components of an uninterruptable powersupply (UPS). In applications where it is too late to incorporate suchfunctionally, external plug-in assemblies are preferred such thatoff-the-shelf UPS systems can be used.

Once a user has installed and configured the power controller 208, aserial communications connection is established. For example, with aterminal or terminal emulation program. Commercial embodiments of thepresent invention that have been constructed use a variety ofcommunications access methods.

For modem access, the communication software is launched that supportsANSI or VT100 terminal emulation to dial the phone number, of theexternal modem attached to the power manager. When the modems connect, auser should see a “CONNECT” message. A user then presses the enter keyto send a carriage return.

For direct RS-232C access, a user preferably starts any serialcommunication software that supports ANSI or VT100 terminal emulation.The program configures a serial port to one of the supported data rates(38400, 29200, 9600, 4800, 2400, 2200, and 300 BPS), along with noparity, eight data bits, and one stop bit, and must assert its DeviceReady signal (DTR or DSR). A user then presses the enter key to send acarriage return.

For Ethernet network connections, the user typically connects to a powercontroller 208 by using a TELNET program or TCP/IP interface. The powermanager will automatically detect the data rate of the carriage returnand send a username login prompt back to a user, starting a session.After the carriage return, a user will receive a banner that consists ofthe word “power manager” followed by the current power manager versionstring and a blank line and then a “Username:” prompt.

A user logged in with the administrative username can control power andmake configuration changes. A user logged in with a general username cancontrol power. Also, while a user logged in with the administrativeusername can control power to all intelligent power modules, a userlogged in with a general username may be restricted to controlling powerto a specific intelligent power module or set of intelligent powermodules, as configured by the administrator.

A related case, U.S. patent application Ser. No. 09/732,557, filed Dec.8, 2000, now U.S. Pat. No. 7,099,934, titled NETWORK-CONNECTED POWERMANAGER FOR REBOOTING REMOTE COMPUTER-BASED APPLIANCES, includes manydetails on the connection and command structure used for configurationmanagement of power manager embodiments of the present invention. Suchpatent application is incorporated herein by reference and the readerwill find many useful implementation details there. Such then need notbe repeated here.

Referring again to FIG. 2, a user at the user terminal 244 is able tosend a command to the power manager 224 to have the power managerconfiguration file uploaded. The power manager 224 concentrates theconfiguration data it is currently operating with into a file. The userat user terminal 244 is also able to send a command to the power manager224 to have it accept a power manager configuration file download. Thedownload file then follows. Once downloaded, the power manager 224begins operating with that configuration if there were no transfer orformat errors detected. These commands to upload and downloadconfiguration files are preferably implemented as an extension to analready existing repertoire of commands, and behind some preexistingpassword protection mechanism. HyperTerminal, and other terminalemulation programs allow users to send and receive files.

In a minimal implementation, the power manager configuration files arenot directly editable because they are in a concentrated format. Itwould, however be possible to implement specialized disassemblers,editors, and assemblers to manipulate these files off-line.

FIG. 3 is a diagram of an expandable power management system 300 thatcan be implemented in the style of the plugstrip 100 (FIG. 1). In onecommercial embodiment of the present invention, a first power controllerboard 302 is daisy-chain connected through a serial cable 303 to asecond power controller board 304. In turn, the second power controllerboard 304 is connected through a serial cable 305 to a third powercontroller board 306. All three power controller boards can communicatewith a user terminal 308 connected by a cable 309, but suchcommunication must pass through the top power controller board 302first.

Alternatively, the user terminal can be replaced by an IP addressinterface that will provide a webpresence and interactive webpages. Ifthen connected to the Internet, ordinary browsers can be used to uploadand download user configurations.

Each power controller board is preferably identical in its hardware andsoftware construction, and yet the one placed at the top of the serialdaisy-chain is able to detect that situation and take on a unique roleas gateway. Each power controller board is similar to power controller208 (FIG. 2). Each power controller board communicates with the othersto coordinate actions. Each power controller board independently storesuser configuration data for each of its power control ports. A typicalimplementation will have four relay-operated power control ports. Partof the user configuration can include a user-assigned name for eachcontrol port.

A resynchronization program is executed in each microprocessor of eachpower controller board 302, 304, and 306, that detects where in theorder of the daisy-chain that the particular power controller board ispreferably located. The appropriate main program control loop isselected from a collection of firmware programs that are copied to everypower controller board. In such way, power controller boards maybefreely added, replaced, or removed, and the resulting group willresynchronize itself with whatever is present.

The top power controller board 302 uniquely handles interactive userlog-in, user-name tables, its private port names, and transferacknowledgements from the other power controller boards. All the otherpower controller boards concern themselves only with their privateresources, e.g., port names.

During a user configuration file upload, power controller board 302begins a complete message for all the power controller boards in thestring with the user-table. Such is followed by the first outletsconfiguration block from power controller board 302, and the otheroutlet configuration blocks from power controller boards 304 and 306.The power controller board 302 tells each when to chime in. Each blockcarries a checksum so transmission errors can be detected. Each blockbegins with a header that identifies the source or destination, then thedata, then the checksum.

During a user configuration file download, power controller board 302receives a command from a user that says a configuration file is next.The user-name table and the serial-name table is received by powercontroller board 302 along with its private outlets configuration blockand checksum. The next section is steered to power controller board 304and it receives its outlets configuration block and checksum. If good,an acknowledgement is sent to the top power controller board 302. Thepower controller boards further down the string do the same until thewhole download has been received. If all power controller boardsreturned an acknowledgement, the power controller board 302 acknowledgesthe whole download. Operation then commences with the configuration.Otherwise a fault is generated and the old configuration is retained.

FIGS. 4A and 4B are power control systems that can be implemented in thestyle of the plugstrip 100 (FIG. 1). FIG. 4A represents a basic powercontrol system 400 that includes four single-point relay boards 401-404that are able to independently control the operating power flowing tovarious pieces of network equipment and other appliances. Each relayboard 401-404 is separately connected to a power manager 406, e.g., witha three-wire cable 407-410 and RJ-11 type plugs and jacks. A user cancontrol the system 400 from a user terminal 412.

FIG. 4B represents an expanded power control system 420 that includesfour four-point relay boards 421-424. This array is able toindependently control the operating power flowing to sixteen pieces ofnetwork equipment and other appliances. Each relay board 421-424 isseparately connected via a serial RS-232 communications link to a powermanager 426, e.g., with a three-wire cable 427-430 and RJ-11 type plugsand jacks. A user can control the system 420 from a user terminal 432.Preferably, the power managers 406 and 426 differ only in theirprogramming, and not in their constituent hardware. Logic level relayboards require only two-wires (control signal and common), but serialrelay boards require three wires (data send, data receive, and common).Even logic level boards use three wires, with the third wire being usedfor the relay board to report power output status (on or off) back tothe power controller circuit board.

Each relay board 421-424 includes a PIC-microcontroller, e.g., aMicrochip Technology (Chandler, Ariz.) PIC16F84A device, that controlsthe serial communication interface with the power manager 426. Serialdata is interpreted by the microcontroller and is used to independentlyoperate each of the relay board's several onboard relays. Such serialcommunication and therefore the microcontroller isn't necessary for therelay boards 401-404 (FIG. 4A).

In a preferred application, the expanded power control system 420 isused instead of daisy-chain connecting power managers to get morecontrol points. For example, power controller boards 304 and 306 (FIG.3) could be eliminated and still as many as sixteen control points canbe accommodated. The configuration in FIG. 3 would otherwise accommodatetwelve control points as shown.

FIG. 5 is a single intelligent power module (IPM) 500 for controllingseveral loads with dry-contact relays. It provides for an alarm to alertwhen too much current is being demanded by one or all of the loadstogether. A serial input/output interface 504 is connected to amicroprocessor 506 with a non-volatile program memory 508. A set of drycontacts 510 are generated from serial data. An over-current alarm 512can issue an external alarm and/or report such condition over the serialcommunication channel 514 to a user display 516 or over a networkinterface controller (NIC) 520.

FIG. 6 represents a four-port current monitor 600, which can be used inaddition to a four-port power module. The current monitor 600 is used tomeasure and report the load current being delivered through each poweroutlet socket. In one embodiment, one of the power mains wires 602 for apower outlet socket is wrapped around a torroid 604 with an air gap. AHall-effect sensor 606 is disposed in the air gap and can measure themagnetic field generated. Such magnetic field will vary in strengthproportional to the current passing through the power mains wires. Acommercial device that has delivered good results is manufactured byAllegro Microsystems, Inc. (Worcester, Mass.), and is marketed as modelA3515LUA. See: “www.allegromicro.com.” An excellent reference thatdescribes how to use such Hall-effect devices in current-measurementapplications is, Allegro Technical Paper STP 98-1, “Non-IntrusiveHall-Effect Current-Sensing Techniques Provide Safe, Reliable Detectionand Protection for Power Electronics”, by Paul Emerald, circa 2001. Alsosee, Allegro Data Sheet 27501.10B, “3515 and 3516 Ratiometric, LinearHall-Effect Sensors for High-Temperature Operation”.

Current monitor 600 further comprises an operational amplifier (op-amp)608 that is combined with a signal diode 610 to precision rectify the ACsignal obtained from Hall-effect device 606. The rectified signal isfiltered and amplified by an op-amp 612. An output signal 614 is a DCvoltage linear with the AC current flowing in the corresponding powermains outlet.

The output of op-amp 612 is input to an analog-to-digital converter(ADC) built into a microcomputer 616. Three other such current sensingcircuits are included, and each respectively produce signals 618, 620,and 622. The microcomputer 616 communicates its four currentmeasurements over a serial input/output (SIO) channel 624. These may bereported to a network operations center via TCP/IP on the Internet, orlocally for a user display. Over-current alarms and thresholds arepreferably programmed in software in the executing programs included inmicrocomputer 616. Such alarms, when issued, can also be reported to thenetwork operations center via TCP/IP, or locally.

Essentially, no calibration is needed. The output of the Hall-effectsensor 606 is typically about 5.0 millivolts per Gauss. With twoturns-on-the torroid 604, the-air gap will fill with 13.8 Gauss per ampof power-main outlet current. Therefore, for a current of 14.142 ampspeak-to-peak, 10.0-amps RMS, the Hall-effect sensor 606 can be expectedto output a sinusoidal signal of about 0.9758 volts p-p.

If the ADC conversion is 8-bits with an analog input voltage range of0-5, each binary bit represents 19.53 millivolts. The input range for atested ADC was thirty amps, about 8-counts per amp. Keeping with thisscaling, the output of the current sensing circuitry at ten amps RMS is1.56 volts.

In general, embodiments of the present invention provide power-onsequencing of its complement of power-outlet sockets so that powerloading is brought on gradually and not all at once. For example, powercomes up on the power outlet sockets 2-4 seconds apart. An exaggeratedpower-up in-rush could otherwise trip alarms and circuit breakers.Embodiments display or otherwise report the total current beingdelivered to all loads, and some embodiments monitor individual poweroutlet sockets. Further embodiments of the present invention provideindividual remote power control of independent power outlet sockets,e.g., for network operations center reboot of a crashed network serverin the field.

The power-on sequencing of the power-outlet sockets preferably allowsusers to design the embodiments to be loaded at 80% of full capacity,versus 60% of full capacity for prior art units with no sequencing. Insome situations, the number of power drops required in a Data Center canthus be reduced with substantial savings in monthly costs.

FIG. 7 represents a power distribution unit (PM) embodiment of thepresent invention, and is referred to herein by the general referencenumeral 700. The PDU 700 allows a personality module 702 to be installedfor various kinds of control input/output communication. A PhilipsSemiconductor type P89C644 microcontroller is preferably included in thepersonality module 702.

The PDU 700 further comprises an I2C peripheral board 704, and a set offour IBM's 706, 708, 710, and 712. Such-provide sixteen power outletsaltogether. A power supply 714 provides +5-volt logic operating power,and a microcontroller with a serial connection to an inter-IC control(I2C) bus 717. Such I2C bus 717 preferably conforms to industrystandards published by Philips Semiconductor (The Netherlands). See,www.semiconductor.philips.com. Philips Semiconductor typemicrocontrollers are preferably used throughout PDU 700 because of theincluded interfaces Philips microcontrollers have for the 12C bus.

A SENTRY-slave personality module 716 can be substituted for personalitymodule 702 and typically includes a Server Technology, Inc. (Reno, NV)SENTRY-type interface and functionality through a standard RJ12 jack.See, www.servertech.com. A chained-slave personality module 718 can besubstituted for personality module 702 and provides a daisy-chain 12Cinterface and functionality through a standard. RJ12 jack. Aterminal-server personality module 720 can be substituted forpersonality module 702 and provides a display terminal interface, e.g.,via 12C through a standard RJ12 jack, or RS-232 serial on a DINconnector. An http personality module 722 can be substituted forpersonality module 702 and provides a hypertext transfer protocol (http)browser interface, e.g., via 100BASE-T network interface and a CAT-5connector. The on-board microcontroller provides all these basicpersonalities through changes in its programming, e.g., stored in EEPROMor Flash memory devices.

All of PDU 700 is preferably fully integrated within power distributionplugstrip 100, in FIG. 1.

FIG. 8 represents a 4-port intelligent power module (IPM) embodiment ofthe present invention, and is referred to herein by the generalreference numeral 800. IPM 800 is like the four IPM's 706, 708, 710, and712, shown in FIG. 7. The IPM 800 includes a set of four power controlchannels 801-804, and a microcontroller 806. The Philips 87LPC762microcontroller has provided good results in this application. Eachpower control channel 801784 includes an input control opto isolator808, single-pole, double throw (SPOT) relay 810, and an output optoisolator 812. A ground (logic low) on IPX_1 will cause relay 810 to pullin. The normally closed (NC) contacts will open, and the normally open(NO) contacts will close. The AC input hot (AC-IN) will be passedthrough to the AC output (AC-OUT) according to a jumper selection for NOor NC operation. If the power is on at AC-OUT, the output opto-isolator812 acts as on on-sense (ONSN) detector to provide an open-collectorlogic signal for a microcontroller status input. The microcontroller 806sends and receives serial data over the 12C bus, and provides the IPM_1,IPM_2, IPM_3, and IPM_4, control signals for all four power controlchannels. The microcontroller 806 can also report the on-off status ofany of the four power control channels 801-804.

The on-sense circuitry of FIG. 8 is such that more than just the powerswitch being switched on has to occur, there must be power actuallyflowing to the relay output to the AC-OUT terminal.

Although the present invention has been described in terms of thepresent embodiment, it is to be understood that the disclosure is not tobe interpreted as limiting. Various alterations and modifications willno doubt become apparent to those skilled in the art after having readthe above disclosure. Accordingly, it is intended that the appendedclaims be interpreted as covering all alterations and modifications asfall within the true spirit and scope of the invention.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thescope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

We claim:
 1. An electrical power distribution system of the type beingconnectable to one or more electrical loads in an electrical equipmentrack, the power distribution system comprising: a power distributionunit enclosure comprising a long, thin, vertical plug-strip bodymountable in a vertical orientation in a back portion of the electricalequipment rack; a power input penetrating the power distribution unitenclosure; a plurality of power outputs disposed in the powerdistribution unit enclosure, wherein each of the plurality of poweroutputs is connectable to a corresponding one of the one or moreelectrical loads; a controllable power section in communication witheach of the plurality of power outputs and an adjustable alarm system,the controllable power section disposed in the power distribution unitenclosure and communicably connectable to a communications networkexternal to the power distribution unit enclosure; and a remote powermanager application communicable with the controllable power sectionthrough the communications network, the remote power manager applicationhaving an adjustable alarm threshold parameter communicable through theremote power manager application to the controllable power section. 2.The electrical power distribution system of claim 1, wherein the alarmthreshold parameter is user-adjustable.
 3. The electrical powerdistribution system of claim 1, wherein the remote power managerapplication is communicable with a remote site through thecommunications network.
 4. The electrical power distribution system ofclaim 3, wherein alarm information can be transmitted from the remotepower manager application to the remote site through the communicationsnetwork.
 5. The electrical power distribution system of claim 1, furthercomprising a voltage sensor communicable with the remote power managerapplication.
 6. The electrical power distribution system of claim 1,further comprising a current sensor communicable with the remote powermanager application.
 7. The electrical power distribution system ofclaim 1, further comprising a temperature sensor communicable with theremote power manager application.
 8. The electrical power distributionsystem of claim 1 and further comprising a plurality ofremotely-controllable switches in communication with the controllablepower section, each switch establishing an interruptible connectionbetween one of the power outputs and the power input.
 9. The electricalpower distribution system of claim 8 wherein the remotely-controllableswitches comprise relays.
 10. The electrical power distribution systemof claim 8 wherein the controllable power section responsive to thealarm system can interrupt the connection between a power output and thepower input.
 11. The electrical power distribution system of claim 10wherein the controllable power section interrupts the connection if theadjustable alarm threshold parameter is exceeded.
 12. The electricalpower distribution system of claim 1 wherein the controllable powersection comprises a plurality of intelligent power modules eachcontaining a microcontroller.
 13. The electrical power distributionsystem of claim 12 wherein the microcontrollers comprise serialcommunication controllers.
 14. The electrical power distribution systemof claim 1 and further comprising an alpha-numeric current display on aface of the power distribution unit enclosure.
 15. The electrical powerdistribution system of claim 14 wherein the current display isswitchable among the power input and various ones of the power outputs.16. The electrical power distribution system of claim 14 wherein thepower outputs are disposed in the same face of the power distributionunit enclosure as the current display.
 17. The electrical powerdistribution system of claim 1 wherein the remote power managerapplication comprises a web browser having an agent in the powerdistribution unit enclosure.
 18. The electrical power distributionsystem of claim 1 and further comprising a communication bus disposed inthe power distribution unit enclosure in electrical communication withthe controllable power section.
 19. The electrical power distributionsystem of claim 1 and further comprising a plurality of current sensorseach in electrical communication with one of the power outputs and withthe controllable power section.
 20. The electrical power distributionsystem of claim 1 and further comprising a personality module disposedin the power distribution unit housing and in electrical communicationwith the controllable power section, the personality module comprising amicrocontroller.